More photos are required to Identify this movement . The appearance of the frame, verge shape and the ST logo suggests that this movement may be from the ST 62 series which had various numbers of escape wheel teeth (30,34,36,40) and at least 5 different versions. Suggest that you take photos of the frame and escape wheel. Measuring the pendulum and running the movement with hands will tell you if the pendulum is approximately correct for this movement. The size of the trapezoidal plates will also help.
The better your photos ---- The better your answer.